1. Thermodynamics Practice

2. Heat Absorbed/Released 1.How many joules of heat are needed to raise the temperature of 10.0 g of magnesium from 22°C to 55°C, if the specific heat of magnesium is 1.02 J/g°C? 2.A 15.75-g piece of iron absorbs 1086.75 joules of heat energy, and its temperature changes from 25°C to 175°C. Calculate the specific heat capacity of iron. 3.A 10.0 g piece of copper is heated and fashioned into a bracelet. The amount of energy transferred by heat to the copper is 6,300 J. If the specific heat of copper is 0.385 J/g 0 C and the copper starts at 26°C, what is the final temperature of the copper?

3. Heat Absorbed/Released 1.q= 340J 2.c=0.46 J/g°C 3.Tf= 1,700 °C

4. Calorimetry 4.A 28.4 g sample of aluminum is heated to 39.4 o C, then is placed in a calorimeter containing 50.0 g of water. The temperature of the water increases from 21.00 o C to 23.00 o C. What is the specific heat of aluminum? 5.A 13.5 g sample of gold is heated, then placed in a calorimeter containing 60.0 g of water. Temperature of water increases from 19.00 o C to 20.00 o C. The specific heat of gold is 0.130 J/g o C. What was the initial temperature of the gold metal sample?

5. Calorimetry 4.c= 0.898 J/g o C 5.Ti= 163 o C

6. Enthalpy 6.According to the following equation, how much heat will be produced when 150.0 grams of sulfur dioxide is produced? S 8 + 8O 2  8SO 2 ∆H= -2,368 KJ 7.What mass of iron must react to release 3,600 KJ of energy? 3Fe + 2O2  Fe3O4 ∆H= -1,120 KJ 8.The following equation describes the reaction that takes place when a typical fat is metabolized by the body: 2C 57 H 104 O 6 + 160O 2  114CO 2 + 104H 2 O∆H= -67,000 KJ How much heat energy must be expelled by the body to rid the body of 450 grams of fat (about 1 pound)?

7. Enthalpy 6.-692.7 KJ 7.540 g 8.-17,000 KJ